Present prizewinner(s) (Guidelines to be updated)
Dr Mathieu Morlighem
University of California, Irvine
for his paper
Deeply incised submarine glacial valleys beneath the Greenland ice sheet
M. Morlighem, E. Rignot, J. Mouginot, H. Seroussi & E. Larour
Nature Geoscience 7, 418–422 (2014); doi:10.1038/ngeo2167
(Citation Abstract Fig. 1 Fig. 2)
Citation for Dr Morlighem by the 2015 Selection Panel:
"In this paper, Dr Morlighem and his colleagues use high resolution satellite measurements of surface elevation and surface ice velocity, plus an ice-mass conservation optimization scheme, to infer ice thickness and bed topography along the periphery of the Greenland ice sheet where the ice is sliding on its base. Their results, which are at a much higher level of spatial detail than previous airborne radar measurements, reveal widespread ice-covered valleys that extend significantly deeper below sea level and farther inland than previously thought. These findings imply that the outlet glaciers of Greenland, and the ice sheet as a whole, are potentially more vulnerable to ocean thermal forcing and peripheral thinning than previously inferred.
Dr Morlighem's paper was awarded the Prize against very strong competition from nominated papers by other Early Career Scientists. The Selection Panel for the Prize expressed their pleasure at the very high standard of the nominated entries. The Prize will be awarded again in 2016."
Ian Allison (Chair), Marilyn N. Raphael, Valérie Masson-Delmotte, and Xiao, Cunde
Abstract: The bed topography beneath the Greenland ice sheet controls the flow of ice and its discharge into the ocean. Outlet glaciers move through a set of narrow valleys whose detailed geometry is poorly known, especially along the southern coasts. As a result, the contribution of the Greenland ice sheet and its glaciers to sea-level change in the coming century is uncertain. Here, we combine sparse ice-thickness data derived from airborne radar soundings with satellite-derived high-resolution ice motion data through a mass conservation optimization scheme. We infer ice thickness and bed topography along the entire periphery of the Greenland ice sheet at an unprecedented level of spatial detail and precision. We detect widespread ice-covered valleys that extend significantly deeper below sea level and farther inland than previously thought. Our findings imply that the outlet glaciers of Greenland, and the ice sheet as a whole, are probably more vulnerable to ocean thermal forcing and peripheral thinning than inferred previously from existing numerical ice-sheet models. [doi:10.1038/ngeo2167]
Details of the large-scale map for Upernavik Isstrøm and Nunatakassaap Sermia (a), Hayes Gletscher, Allison Gletscher and Illullip Sermia (b), Petermann, Steensby and Ryder Gletscher (c), Marie Sophie Gletscher, Academy Gletscher and Hagen Bræ (d), F. Graae, Charcot and Daugaard-Jensen (e), and Kangerlussuaq Gletscher (f); glaciers are listed in clockwise order. The white contour line delineates the limit of land ice. The mass conservation method is employed for the glaciers. Kriging is used to map the interior regions. [doi:10.1038/ngeo2167]
Profiles A (a), B (b) and C (c), with their locations given in d, show the surface elevation in black, reference sea level in dashed black, bed topography B2001 from ref. 7 in brown, B2013 from ref. 16 and associated error in green, the mass conservation topography and associated error (2σ) in blue, and OIB bed elevation derived from radar tracks as black squares with error bars. (d), Locations of the profiles A, B and C are shown as white lines, with a bed topography colour-coded between −900 and +1,300 m, overlaid on a radar mosaic of Greenland. Profiles B and C coincide with OIB flight lines. [doi:10.1038/ngeo2167]